Police officers detain Chunli Zhao in Half Moon Bay, California, on January 23.
CNN  — 

Five of the seven people killed in the Half Moon Bay shootings in California were Chinese citizens, China’s consulate in San Francisco said Thursday.

The consulate strongly condemned the killings, which took place in the San Francisco Bay area on Monday, and sent its condolences to the victims’ families.

“We are in close contact with relative departments in the US and actively monitoring any update of the investigation,” the statement said. “In the meantime, we have gotten in touch with the family members of most of the victims, and will do as much as we can to provide consular assistance.”

The shootings took place in a small coastal community, at a mushroom farm and another site about two miles away. It was the state’s second mass shooting in three days after the Monterey Park attack, which left 11 people dead.

The suspect in the Half Moon Bay shootings, 66-year-old Chunli Zhao, is a Chinese citizen who was not previously known to local law enforcement – though he has been accused of violence before, and was subject to a temporary restraining order after a former coworker and roommate accused him of attacking and threatening him in 2013.

Zhao was arrested Monday, and formally charged Wednesday with seven counts of murder and one count of attempted murder by the San Mateo District Attorney’s Office.

Questions remain about what could have motivated the shooting. But officials said Tuesday the attack was a “workplace violence incident,” and that Zhao had targeted specific people. He was a “coworker or former coworker” of the victims at each shooting site, the San Mateo County Sheriff’s office said.

Authorities believe Zhao acted alone.

On Thursday, NBC Bay Area reported that Zhao had confessed to the attacks and said he regrets them, after the channel interviewed the suspect in jail.

The interview was conducted in Mandarin by NBC Bay Area reporter Janelle Wang, with the two speaking face to face for about 15 minutes, Wang said.

Wang said he told her he doesn’t “know what was happening mentally” in the moment of the shootings, and that he wasn’t in his right mind.

CNN has not been able to independently confirm what Zhao said in the interview and has reached out to his attorneys for comment.

CNN’s Taylor Romine, Samira Jafari and Paradise Afshar contributed reporting.